Some people acting like being labeled a "brawler" is like degrading a boxer. Thats not true. The "brawler" style is a style all of its own and there are skilled ATG brawlers like Hagler and JCC. Others are super crude like Ward. Prime Tyson fought as a brawler-stalker and he was highly skilled. You can be super skilled yet fight as a brawler. The two terms arent mutually exclusive. The best example of a good brawler beating a good boxer puncher imho is Hagler-Hearns.
That was one of the only fights in which Hagler fought like a brawler though. That was a boxer-puncher switching to a brawler for that particular night. One of the best "out of character" performances ever.
Brawlers who have both speed and power are Tyson and Pacquiao. And I agree that the term brawler can be described by the situation too. Like Hearns v.s. Hagler as someone gave it above as an example.
I can't name the top 5, but when I think of the quintessential brawlers, I think of Jack Dempsey, Arturo Gatti (post-Patterson II), Jeff Fenech, Little Red Lopez, Rocky Graziano and Jake LaMotta. Maybe Frazier as well. I don't tend to draw much of a line between a brawler and a swarmer though. I think some would probably describe a few of those guys as more of a swarmer.